include/linux/memory_hotplug.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_MEMORY_HOTPLUG_H
   3 #define __LINUX_MEMORY_HOTPLUG_H
   4
   5 #include <linux/mmzone.h>
   6 #include <linux/spinlock.h>
   7 #include <linux/notifier.h>
   8 #include <linux/bug.h>
   9
  10 struct page;
  11 struct zone;
  12 struct pglist_data;
  13 struct mem_section;
  14 struct memory_group;
  15 struct resource;
  16 struct vmem_altmap;
  17 struct dev_pagemap;
  18
  19 #ifdef CONFIG_MEMORY_HOTPLUG
  20 struct page *pfn_to_online_page(unsigned long pfn);
  21
  22 /* Types for control the zone type of onlined and offlined memory */
  23 enum {
  24         /* Offline the memory. */
  25         MMOP_OFFLINE = 0,
  26         /* Online the memory. Zone depends, see default_zone_for_pfn(). */
  27         MMOP_ONLINE,
  28         /* Online the memory to ZONE_NORMAL. */
  29         MMOP_ONLINE_KERNEL,
  30         /* Online the memory to ZONE_MOVABLE. */
  31         MMOP_ONLINE_MOVABLE,
  32 };
  33
  34 /* Flags for add_memory() and friends to specify memory hotplug details. */
  35 typedef int __bitwise mhp_t;
  36
  37 /* No special request */
  38 #define MHP_NONE                ((__force mhp_t)0)
  39 /*
  40  * Allow merging of the added System RAM resource with adjacent,
  41  * mergeable resources. After a successful call to add_memory_resource()
  42  * with this flag set, the resource pointer must no longer be used as it
  43  * might be stale, or the resource might have changed.
  44  */
  45 #define MHP_MERGE_RESOURCE      ((__force mhp_t)BIT(0))
  46
  47 /*
  48  * We want memmap (struct page array) to be self contained.
  49  * To do so, we will use the beginning of the hot-added range to build
  50  * the page tables for the memmap array that describes the entire range.
  51  * Only selected architectures support it with SPARSE_VMEMMAP.
  52  * This is only a hint, the core kernel can decide to not do this based on
  53  * different alignment checks.
  54  */
  55 #define MHP_MEMMAP_ON_MEMORY   ((__force mhp_t)BIT(1))
  56 /*
  57  * The nid field specifies a memory group id (mgid) instead. The memory group
  58  * implies the node id (nid).
  59  */
  60 #define MHP_NID_IS_MGID         ((__force mhp_t)BIT(2))
  61 /*
  62  * The hotplugged memory is completely inaccessible while the memory is
  63  * offline. The memory provider will handle MEM_PREPARE_ONLINE /
  64  * MEM_FINISH_OFFLINE notifications and make the memory accessible.
  65  *
  66  * This flag is only relevant when used along with MHP_MEMMAP_ON_MEMORY,
  67  * because the altmap cannot be written (e.g., poisoned) when adding
  68  * memory -- before it is set online.
  69  *
  70  * This allows for adding memory with an altmap that is not currently
  71  * made available by a hypervisor. When onlining that memory, the
  72  * hypervisor can be instructed to make that memory available, and
  73  * the onlining phase will not require any memory allocations, which is
  74  * helpful in low-memory situations.
  75  */
  76 #define MHP_OFFLINE_INACCESSIBLE        ((__force mhp_t)BIT(3))
  77
  78 /*
  79  * Extended parameters for memory hotplug:
  80  * altmap: alternative allocator for memmap array (optional)
  81  * pgprot: page protection flags to apply to newly created page tables
  82  *      (required)
  83  */
  84 struct mhp_params {
  85         struct vmem_altmap *altmap;
  86         pgprot_t pgprot;
  87         struct dev_pagemap *pgmap;
  88 };
  89
  90 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
  91 struct range mhp_get_pluggable_range(bool need_mapping);
  92 bool mhp_supports_memmap_on_memory(void);
  93
  94 /*
  95  * Zone resizing functions
  96  *
  97  * Note: any attempt to resize a zone should has pgdat_resize_lock()
  98  * zone_span_writelock() both held. This ensure the size of a zone
  99  * can't be changed while pgdat_resize_lock() held.
 100  */
 101 static inline unsigned zone_span_seqbegin(struct zone *zone)
 102 {
 103         return read_seqbegin(&zone->span_seqlock);
 104 }
 105 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
 106 {
 107         return read_seqretry(&zone->span_seqlock, iv);
 108 }
 109 static inline void zone_span_writelock(struct zone *zone)
 110 {
 111         write_seqlock(&zone->span_seqlock);
 112 }
 113 static inline void zone_span_writeunlock(struct zone *zone)
 114 {
 115         write_sequnlock(&zone->span_seqlock);
 116 }
 117 static inline void zone_seqlock_init(struct zone *zone)
 118 {
 119         seqlock_init(&zone->span_seqlock);
 120 }
 121 extern void adjust_present_page_count(struct page *page,
 122                                       struct memory_group *group,
 123                                       long nr_pages);
 124 /* VM interface that may be used by firmware interface */
 125 extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
 126                                      struct zone *zone, bool mhp_off_inaccessible);
 127 extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages);
 128 extern int online_pages(unsigned long pfn, unsigned long nr_pages,
 129                         struct zone *zone, struct memory_group *group);
 130 extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
 131                 unsigned long end_pfn);
 132
 133 typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
 134
 135 extern void generic_online_page(struct page *page, unsigned int order);
 136 extern int set_online_page_callback(online_page_callback_t callback);
 137 extern int restore_online_page_callback(online_page_callback_t callback);
 138
 139 extern int try_online_node(int nid);
 140
 141 extern int arch_add_memory(int nid, u64 start, u64 size,
 142                            struct mhp_params *params);
 143 extern u64 max_mem_size;
 144
 145 extern int mhp_online_type_from_str(const char *str);
 146
 147 /* Default online_type (MMOP_*) when new memory blocks are added. */
 148 extern int mhp_default_online_type;
 149 /* If movable_node boot option specified */
 150 extern bool movable_node_enabled;
 151 static inline bool movable_node_is_enabled(void)
 152 {
 153         return movable_node_enabled;
 154 }
 155
 156 extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap);
 157 extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
 158                            struct vmem_altmap *altmap);
 159
 160 /* reasonably generic interface to expand the physical pages */
 161 extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 162                        struct mhp_params *params);
 163
 164 #ifndef CONFIG_ARCH_HAS_ADD_PAGES
 165 static inline int add_pages(int nid, unsigned long start_pfn,
 166                 unsigned long nr_pages, struct mhp_params *params)
 167 {
 168         return __add_pages(nid, start_pfn, nr_pages, params);
 169 }
 170 #else /* ARCH_HAS_ADD_PAGES */
 171 int add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 172               struct mhp_params *params);
 173 #endif /* ARCH_HAS_ADD_PAGES */
 174
 175 void get_online_mems(void);
 176 void put_online_mems(void);
 177
 178 void mem_hotplug_begin(void);
 179 void mem_hotplug_done(void);
 180
 181 /* See kswapd_is_running() */
 182 static inline void pgdat_kswapd_lock(pg_data_t *pgdat)
 183 {
 184         mutex_lock(&pgdat->kswapd_lock);
 185 }
 186
 187 static inline void pgdat_kswapd_unlock(pg_data_t *pgdat)
 188 {
 189         mutex_unlock(&pgdat->kswapd_lock);
 190 }
 191
 192 static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat)
 193 {
 194         mutex_init(&pgdat->kswapd_lock);
 195 }
 196
 197 #else /* ! CONFIG_MEMORY_HOTPLUG */
 198 #define pfn_to_online_page(pfn)                 \
 199 ({                                              \
 200         struct page *___page = NULL;            \
 201         if (pfn_valid(pfn))                     \
 202                 ___page = pfn_to_page(pfn);     \
 203         ___page;                                \
 204  })
 205
 206 static inline unsigned zone_span_seqbegin(struct zone *zone)
 207 {
 208         return 0;
 209 }
 210 static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
 211 {
 212         return 0;
 213 }
 214 static inline void zone_span_writelock(struct zone *zone) {}
 215 static inline void zone_span_writeunlock(struct zone *zone) {}
 216 static inline void zone_seqlock_init(struct zone *zone) {}
 217
 218 static inline int try_online_node(int nid)
 219 {
 220         return 0;
 221 }
 222
 223 static inline void get_online_mems(void) {}
 224 static inline void put_online_mems(void) {}
 225
 226 static inline void mem_hotplug_begin(void) {}
 227 static inline void mem_hotplug_done(void) {}
 228
 229 static inline bool movable_node_is_enabled(void)
 230 {
 231         return false;
 232 }
 233
 234 static inline bool mhp_supports_memmap_on_memory(void)
 235 {
 236         return false;
 237 }
 238
 239 static inline void pgdat_kswapd_lock(pg_data_t *pgdat) {}
 240 static inline void pgdat_kswapd_unlock(pg_data_t *pgdat) {}
 241 static inline void pgdat_kswapd_lock_init(pg_data_t *pgdat) {}
 242 #endif /* ! CONFIG_MEMORY_HOTPLUG */
 243
 244 /*
 245  * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
 246  * platforms might override and use arch_get_mappable_range()
 247  * for internal non memory hotplug purposes.
 248  */
 249 struct range arch_get_mappable_range(void);
 250
 251 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
 252 /*
 253  * pgdat resizing functions
 254  */
 255 static inline
 256 void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
 257 {
 258         spin_lock_irqsave(&pgdat->node_size_lock, *flags);
 259 }
 260 static inline
 261 void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
 262 {
 263         spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
 264 }
 265 static inline
 266 void pgdat_resize_init(struct pglist_data *pgdat)
 267 {
 268         spin_lock_init(&pgdat->node_size_lock);
 269 }
 270 #else /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
 271 /*
 272  * Stub functions for when hotplug is off
 273  */
 274 static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
 275 static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
 276 static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
 277 #endif /* !(CONFIG_MEMORY_HOTPLUG || CONFIG_DEFERRED_STRUCT_PAGE_INIT) */
 278
 279 #ifdef CONFIG_MEMORY_HOTREMOVE
 280
 281 extern void try_offline_node(int nid);
 282 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 283                          struct zone *zone, struct memory_group *group);
 284 extern int remove_memory(u64 start, u64 size);
 285 extern void __remove_memory(u64 start, u64 size);
 286 extern int offline_and_remove_memory(u64 start, u64 size);
 287
 288 #else
 289 static inline void try_offline_node(int nid) {}
 290
 291 static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 292                                 struct zone *zone, struct memory_group *group)
 293 {
 294         return -EINVAL;
 295 }
 296
 297 static inline int remove_memory(u64 start, u64 size)
 298 {
 299         return -EBUSY;
 300 }
 301
 302 static inline void __remove_memory(u64 start, u64 size) {}
 303 #endif /* CONFIG_MEMORY_HOTREMOVE */
 304
 305 #ifdef CONFIG_MEMORY_HOTPLUG
 306 extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
 307 extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
 308 extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
 309 extern int add_memory_resource(int nid, struct resource *resource,
 310                                mhp_t mhp_flags);
 311 extern int add_memory_driver_managed(int nid, u64 start, u64 size,
 312                                      const char *resource_name,
 313                                      mhp_t mhp_flags);
 314 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 315                                    unsigned long nr_pages,
 316                                    struct vmem_altmap *altmap, int migratetype);
 317 extern void remove_pfn_range_from_zone(struct zone *zone,
 318                                        unsigned long start_pfn,
 319                                        unsigned long nr_pages);
 320 extern int sparse_add_section(int nid, unsigned long pfn,
 321                 unsigned long nr_pages, struct vmem_altmap *altmap,
 322                 struct dev_pagemap *pgmap);
 323 extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
 324                                   struct vmem_altmap *altmap);
 325 extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
 326                                           unsigned long pnum);
 327 extern struct zone *zone_for_pfn_range(int online_type, int nid,
 328                 struct memory_group *group, unsigned long start_pfn,
 329                 unsigned long nr_pages);
 330 extern int arch_create_linear_mapping(int nid, u64 start, u64 size,
 331                                       struct mhp_params *params);
 332 void arch_remove_linear_mapping(u64 start, u64 size);
 333 #endif /* CONFIG_MEMORY_HOTPLUG */
 334
 335 #endif /* __LINUX_MEMORY_HOTPLUG_H */